183 
Sclerotinece as examples of this. But such a luxuriant growth, connected 
with such a high degree of cell division, which simultaneously produces 
the growth of a mycelium from the spore, and chauges the latter into a 
new and complicated organ of reproduction, can scarcely have been ob¬ 
served before. 
But the case presents a further point of interest when compared with 
the formation of other pycnidia. We may discriminate between a 
% 
symphyogenous and a meristogenous development. Pycnidia arise 
symphyogenously by an interweaving of hyphae and meristogeuously 
by the growth and division into cells of a piece of hypha in which the 
branches of the hypha may share. The sporopycnidium is there¬ 
fore meristogenous even if it does not arise from a mycelial thread. It 
represents rather the most extreme case of meristogenous develop¬ 
ment, arising directly from the division and growth of the spore without 
the interposition of any foreign element. 
Before the formation of this sporopycnidium is completed the begin¬ 
nings of new pycnidia arise at the periphery of the mycelium. These 
are of meristogenous origin, yet several hyphae are concerned in their 
construction. One or several cells swell up anywhere upon a hypha 
(Figs. 17-18), and these become divided by walls which are laid down 
both in transverse and longitudinal directions. In the vicinity of these 
spots the hyphae which bound and those which accidentally cross or 
touch them exhibit the same changes, their cells also enlarging aud di¬ 
viding. In this way these hyphae nearly fasten themselves to each 
other. Through continued growth and cell division there arises a many- 
celled compact body from which many hyphae apparently originate ; but 
it is from them that the body itself arose. The young pycnidia may 
attain considerable size without showing any cavity (Fig. 19). At first 
no differentiation can be seen until the walls of the superficial cells be¬ 
come thickened and brown. The single cells also increase in size with 
the growth of the whole, but the central portion finally falls behind the 
periphery, and the cells separate from each other in the center, without, 
however, as Bauke has shown for Gucurbitaria elongata , the process be¬ 
ing begun by a very large definite cell. In this way there arises a cav¬ 
ity which enlarges with the growth of the pycnidium (Fig. 20) and is 
lined by uniform cells. From these grow out filiform basidia, which 
form a hymenium and cut off very small spores (Fig. 21). The outer 
wall of the pycnidium is now composed of cells whose contents have 
been transformed into a dark-colored mass, while the membranes them¬ 
selves are less deeply colored. Here also are the beginnings of a special 
pore, as is the case in the sporopycnidium. 
These pycnidia develop in essentially the same manner described by 
Bauke for Gucurbitaria elongata ; but with this difference, that here 
the hyphae which lie against the beginnings of the pycnidium do not 
merely form the envelope, but instead all the elements have the same 
functions, as is shown by cross-sections through quite young stages. 
